Feel free to talk to us! Phone Number: 973-366-4660

Mold Control Information Series – Article #3

If you need mold control assistance discussed in this article call us at 973-366-4660 or e-mail us at info@atlenv.com for details and a free estimate.

Written By:  Robert E. Sheriff, MS, CIH, CSP, President
April 22, 2020

Mold Control 

After the Flood: Preventing Mold

Beyond the direct water damage from a flood, there can be short term and long term problems with mold growth, whether the building is commercial or residential.

The source of water is the first important issue.   Consider the following for mold control after a flood:

1). If the flood is from surface water floodings such as heavy rains, hurricanes, and overflowing rivers, this means dirt and debris.  The debris is a rich growth environment for mold and bacteria as well.  It is full of lawn fertilizer, topsoil, plant debris, and even sewage that promotes many microorganisms to grow – and rapidly – probably as fast as a few days during warm weather.  Also consider that the humidity is 80-90°, during the rainy season in most parts of the country.  Wonderful if you’re a mold!

This debris will fully penetrate carpets, cloth-covered surfaces, and wallboards with little chance they can be thoroughly cleaned or disinfected. With few exceptions, the only remedy is removal and replacement.  It is important to note that bacteria can contaminate all surfaces where possible septic waste is involved.  Testing for E. coli is important.  If the flooding is minimal with limited debris, vacuuming and dehumidifying within the first few days may save some of those surfaces.

2). If the flood is from a backed-up sewer, then it is obvious that both mold and bacteria are important issues that must be addressed. Replacement of ducts and contacted surfaces is highly advised.  Very thorough cleaning of clothing and other fabrics is essential (dry cleaning won’t work since it doesn’t disinfect).  Cleaning of all dirt and debris is as important as removing mold or bacteria since the microorganisms can exist in a dormant state and only need a “little something to eat,” such as dirt.

3). Flooding from a broken or leaking water line is not to be dismissed as a non-microbial event.  Since small quantities of molds and mold spores are essentially everywhere (in the air and on most horizontal and vertical surfaces), they only need a source of moisture and food which can be: a) the cellulose in sheetrock; b) wood; c) cotton, wool or other natural fibers; and d) dust/dirt that accumulates over time.

Preventing Mold Growth After a Flood

Regardless of the source and the specifics mentioned above, there are some things that can be done to prevent or control mold growth after a flood.

First:   Clean-Up

The first is to clean up and remove all damaged or destroyed furnishings or building materials as soon as possible.  Within a few days at most.  This will reduce mold growth and the quantity of mold and spores that can multiply and be dislodged to settle elsewhere. If allowed time to infest an area, just the demolition process itself can release millions, even billions, of spores.


Dehumidify the area even while clean-up is going on – don’t wait until demolition is complete. Those little microbes aren’t shy; they’ll grow whether they see you or not.  Take away their moisture and growth will cease.  The ideal is to get it to 50% relative humidity or less.

NEXT –Reduce Temperature

Air conditioning or keeping the area cool can be very effective.  Air conditioning dehumidifies as well as cools, which removes heat and moisture, both of which are essential for mold growth.  In the absence of dehumidifiers, A/C will help.

Use Mold Resistant Building Materials

Remember that wood, spaces behind walls, underneath furniture, equipment, appliances, and even sub-flooring can harbor water or high levels of moisture that are very conducive to mold propagation.  If moisture is a long term problem, replacing the material with non-porous or less porous material is advisable, such as green board (water-resistant sheetrock), hardboard, metal studs, and ceramic tile.


Fungicidal paint can be used to retard (not eliminate) mold growth in areas that have been wet or damp over an extended period of time.  They must be dried out before painting or they will just blister from the inside-out.  Most major manufacturers of household and commercial paint carry a line of fungicidal paints specifically developed to prevent mold growth after application.

Controlling microbial growth after flooding is a subject that can (and does) cover volumes.  This article just summarizes some of the most important aspects of this very complex subject. Consulting an expert should be considered in severe cases or for large buildings.

Atlantic Environmental is here to help you with mold growth issues and to provide you with essential mold growth information regarding your individual situation. Contact us today to learn more and get help.

Our primary service areas for Mold Control After a Flood Services are New Jersey NJNew York NY, (New York City)Pennsylvania PAConnecticut CTDelaware DEMassachusetts, (Boston) MARhode Island RIWashington DCWisconsin WIMaryland MDMichigan MIIllinois (Chicago) ILVirginia VAIndiana INGeorgia (Atlanta) GAAlabama ALNorth Carolina NCSouth Carolina SCTennessee TNTexas (Dallas, Ft Worth) TXOklahoma OKDCArkansas AR, Florida FL. We can service most other areas of the U.S. but with some added travel charges.

This entry was posted in Indoor Air Quality (IAQ) News & Technical articles, Uncategorized and tagged . Bookmark the permalink.